Several types of non-volatile (NV) memory technologies are being developed to serve as “system memory” in a computer system to replace the common dynamic random access memory (DRAM). The NV memory technologies typically have slow read and write times. To improve the slow read and write times of the NV memory, “hybrid” memories may be employed. In one type of hybrid memory, a large block of NV memory may have a static or dynamic RAM as a buffer/cache. Write operations may be written to and confirmed from the static or dynamic RAM to mask the slow read and write times of the NV memory.
These hybrid memories typically lose the data in the static or dynamic RAM when power is interrupted. Some hybrid memories include a battery backup to copy the entire contents of the static or dynamic RAM to a flash memory when power is interrupted. The battery capacity required to copy the entire contents of the static or dynamic RAM, however, may require undesirably large batteries.